1. Field of the Disclosure
The present invention relates to a quantum dot light emitting element which can form a quantum light emitting layer configured of charge transporting particles and quantum dots and a charge transporting layer in a solution process, to reduce process expense, and a method for manufacturing the same.
2. Discussion of the Related Art
Quantum dot (QD) is a semiconductor nanoparticle, with the quantum dot of a nanometer size emits a light when an electron of an unstable state is moving downward to a valence band from a conduction band. As a particle of the quantum dot is smaller, a light having a shorter wavelength is generated. As the particle of the quantum is larger, a light having a long wavelength is generated. This is a unique electrical optical characteristic of the quantum dot, different from the other conventional semiconductor elements. Because of that, when the size of the quantum dot is adjusted, a visible ray having a desired wavelength can be presented. Quantum dots having various sizes may be used to present various colors simultaneously.
Compared with an organic light emitting element, a quantum dot light emitting element uses the quantum dot to form a light emitting layer instead of an organic light emitting material. An organic light emitting diode (OLED) using the organic light emitting material presents a single color, for example, white, red and blue based on a type of a diode. The organic light emitting diode has limitation of presenting a variety of colors magnificently. In contrast, the quantum dot light emitting element controls the size of the quantum dot and it can present desired natural colors. In addition, the quantum dot light emitting element has good color presentation and good brightness, compared with a light emitting diode. Because of that, the quantum dot light emitting element is drawing attention to overcome a disadvantage of the light emitting diode spotlighted as next generation light source.
As follows, a structure of a conventional quantum dot light emitting element will be described.
FIG. 1 is a sectional view of a conventional quantum dot light emitting element.
In reference to FIG. 1, the quantum dot light emitting element includes an anode 10 and a cathode 50 opposed to each other on a substrate 100, and a quantum light emitting layer 30 formed between the anode 10 and the cathode 50, with a plurality of quantum dots 31. A hole transporting layer 20 configured of hole transporting particles is formed on the anode 10 and the quantum light emitting layer 30 is formed on the hole transporting layer 20. An electron transporting layer 40 configured of electron transporting particles and the cathode 50 are formed on the quantum light emitting layer 30 sequentially.
The hole transporting layer 20 transports and injects holes to the quantum dots 31 of the quantum light emitting layer 30 from the anode 10. Similarly, electrons injected in the cathode 50 are transported and injected to the quantum dots 31 of the quantum light emitting layer 30 by the electron transporting layer 40.
However, such the conventional quantum dot light emitting element is configured of four or more layers except an electrode and the structure of the conventional quantum dot light emitting element is complex. In addition, most of the layers except the quantum light emitting layer 30 are formed in a vacuum deposition process and a process chamber for the quantum dot light emitting element has to be provided accordingly. As a result, manufacture cost of the quantum dot light emitting element might be increased disadvantageously and process time might be increased.